Attachment for screw-threading machines



Feb. 11, 1930. J. A. AKEROYD ATTACHMENT FOR SCREW THREADING MACHINES Filed Dec. 28, 192.7 2 Sheets-Sheet 2 JEV'YEN TOR 272m 2:15 .21. 5:53. 03:0,

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pummel-"eh. 11, 1930 UNITED STATES PATENT OFFICE JULIUS A. AKEROYD, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR T0 GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK ATTACHMENT FOR SCREW-THREADIN G MACHINES Application filed December 28, 1927. Serial No. 243,121.

My invention relates to machines for screw-threading sheet-metal articles, such as blanks for incandescent lamp bases and similar articles. More particularly my invention relates to means for removing the completed screw-threaded article from the die upon which it is supported. My invention provides means for removing the article mechanically from a full-size inner die roll. Heretofore such mechanical removal has been provided only where the inner die roll was substantially smaller in diameter than the blank.

According to my invention, after the screw-threading operation is completed, a dofi'er is brought to bear against the blank, and the continued rotation of the inner die roll causes the blank to unscrew from the said roll. Means are preferably provided for moving the doifer with the blank and at the same speed as it unscrews from the die roll. The mechanism for accomplishing these results is combined with the screw-threading mechanism so that the parts function in proper time relation. Other features and advantages of my invention will appear from the description of a species thereof which follows and from the accompanying drawlngs.

In the drawings Fig. 1 is a plan view of an automatic screw-threading machine embodying my invention; Fig. 2 is an elevation thereof partially in section; Fig. 3 is an end elevation of the drive for the outside threading die; Fig. 4 is a fragmentary plan view on an enlarged scale of the blank-loading mechanism; Fig. 5 is a fragmentary elevation on an enlarged scale of the threading dies and dofier arm; Fig. 6 is an elevation artially in section of a cup-shaped metal b ank prior to being threaded; and Fig. 7 is an elevation of the said blank after the threading operation has been completed.

As shown in the drawings, the articles to be threaded, which in this particular case are cup-shaped metal blanks 10, are held in a chute or magazine 11 which rests on the top of bracket 12 attached to machine base 13 which in turn is supported by legs 14. The chute 11 is inclined so that the blanks will move by gravity toward the bottom thereof 'et 12 and has fastene where there is located a horizontal plate 15. The plate 15 is slidabl mounted in the brackto one end thereof an arm 16 shaped so as to receive one blank at a time from the end of the chute. The plate is then moved so that its arm 16 will carry a blank forward to a position oppositeand in line with the inside threading die 17 as shown in Fig. 4. A cam 18 mounted on shaft 19 sup orted in bearings 20 formed in the bracket 2 and bearing 20 extending from base 13 advances and retracts the plate 15 through roller 21, lever 22 pinned to shaft 23. The shaft 23 carries at its opposite end a lever 24 which is connected to the sliding late 15 through link 25. A spring 26 keeps t e roller 21 in contact with the cam 18. The shaft 19 to which is keyed the cam 18 is rotated by pinion 27 which meshes with pinion 28 mounted on shaft 19. Pinion 27 is mounted on one end of shaft 29 whose opposite end carries pinion 30 which meshes with pinion 31 mounted on shaft 32, said shaft bein rotated through pulle 33 which is driven rom an outside source 81 1013 shown).

As shown in Fig. 4, the blank 10 has been carried in arm 16 to a position opposite and in line with the inside threading die 17 by the advancement of plate 15. A pin 34 alined with the said die is next moved forward in the direction of arrow A to push the blank 10 off the arm 16 and onto the die 17 as shown in dotted lines. The pin 34 extends from an arm 35 carried on rod 36. The said rod is slidably'mounted in bearings 37 and operated through a cam 38 keyed to shaft 29. The cam 38 transmits its motion to roller 39 carried on one arm of a crank 40, the other arm of which carries a rod 41 which is connected to the sliding rod 36 through crosshead 42. A rod 43 extending between the bearings 37 acts as a guide for the cross-head 42.

After a blank 10 has been placed on the inside threading die 17, an outside threading die 44 of somewhat larger diameter is moved toward the inside die to contact with the blank and the threading of the blank is accomplished by rotating the dies in op osite directions. The die 17 is carried on t e end of 1 shaft 45 which is continuously rotated through belt and pulley 46 and 47 respectively. The die 44 is mounted on shaft 48 rotatably supported in rocker arm 49. R0- tation from shaft 45 is communicated to shaft 48 through intermeshing gears 49 and 50 and shaft 51. The shaft 51 carries at its opposite end another gear 52 which drives gear 53 keyed on shaft 48 through idler gear 54 as shown in Fig. 3. The die 44 is brought into operative relationship with die 17 by reason of the fact that the rocker arm '49 carries a roller 55 which rides on cam 56 mounted on shaft 32. The shape of the cam is such as to lower and raise the rocker arm at the proper time.

When the threading o eration is completed, the blank is removed fiom the .die 17 by a dofi'er arm 57 which is brought into operation by the action of a cam 58, said arm being held against the cam by a spring 59. The arm 57 moves about a sleeve 60 as a center so as to cause a pad 61 of leather ,or other friction material adjustably supported in holder 62 extending from said arm to contact with the lower side of the threaded shell formed from the blank 10. The arm is moved in a lateral direction by cam 63 against which it is held by a spring 64. The shape of the cam is such that it will move the arm.57 so as to cause the'pad G1 to travel along the surface of the shell at-a speed equal to the lateral travel of the helix of the thread. \Vhen the arm has arrived at the end of the die, the cam 58 causes the dolfer arm 57 to lift away from the said die and the arm is moved back to its initial position by cam 63. Cams 58 and (33 are mounted on shaft 65 supported in bearings 66 and G7 and said shaft carries at its end a gear (38. The gear 68 is driven from gear 69 mounted on shaft 32. In order to prevent possible rebound of the dofi'er arm 57. a stop 70 is provided.

7 hat I claim as new and desire to secure by Letters Patent of the United States is 1. In a machine for screw-threading metal shells, the combination of inner and outer threaded die rolls, means for rotating said rolls, a dofi'er mounted adjacent to said inner 'die roll and movable into and out of frictional engagement with the shell held there-' by, and means for causing the said doffer to bear against the shell and hold it stationary after the threading operation so that the continued rotation of the inner die roll effects a removal'of the shell.

2. In a machine for screw threading metal shells, the combination of inner and outer threaded die rolls, means for rotating said rolls, a dotfer mounted adjacent to said inner die roll and movable into and out of frictional engagement with the shell held thereby, and means for causing the said dofl'er to bear against the shell and'hold it stationary after the threading operation so that the continued rotation of the inner die roll effects a. removal of the shell, and means whereby the aforesaid means are caused to operate in proper time relation.

3. In a machine for screw-threading metal shells, the combination with inner and outer threaded die rolls, means for feeding shells one at a time onto said inner die roll, and means for performing the screw-threading operation including rotating means for said rolls; of means for subsequently removing the screw-threaded shell comprising a doffer mounted adjacent to said inner die roll and movable into and out of frictional enga ement with the shell held thereby, means or moving the said doffer into engagement with the screw-threaded portion of said shell,-and means for causing it to move with the shell as it unscrews from the inner die roll.

4. In a machine for screw-threading metal shells. the combination with inner and outer threaded die rolls, means for feeding shells one at a time onto said inner die roll, and means for performing the screw-threading operation including rotating means for said rolls; of means for subsequently removing the screw-threaded shell comprisin a doffer mounted adjacent to said inner ie roll and movable into and out of frictional enga ement with the shell held thereby, means or moving the said doffcr into engagement with the screw-threaded portion of said shell, means for causing it to move with the shell as it unscrews from the inner die roll, and means whereby said parts are caused to operate in proper time relation.

5. The combination of means for screwthreading metal shells, comprising inner and outer screw-threaded die rolls, means for rotating said rolls, means for feeding shells onto said inner roll, means for subsequently bringing said outer roll into engagement with said shell, and means for removing the com-.

pleted screw-threaded shell comprising a doffer mounted adjacent to said inner die roll and movable into and out of-frictional engagement with the shell held thereby, means for causing the said doffer to contact with said shell and to hold it against rotation while the rotation of the inner die roll unscrews it therefrom, and means whereby said parts are caused to operate in proper time relation.

In witness whereof, I have hereunto set my hand this 23d day of December, 1927.

JULIUS A. AKEROYD. 

